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101.
Molecular modelling and simulation as well as four equations of state (EOS) are applied to natural gas mixtures regarding Joule–Thomson (JT) inversion. JT inversion curves are determined by molecular simulation for six different natural gas mixtures consisting of methane, nitrogen, carbon dioxide and ethane. These components are also regarded as pure fluids, leading to a total of 10 studied systems. The results are compared to four advanced mixture EOS: DDMIX, SUPERTRAPP, BACKONE and the recent GERG-2004 Wide-Range Reference EOS. It is found that molecular simulation is competitive with state-of-the-art EOS in predicting JT inversion curves. The molecular based approaches (simulation and BACKONE) are superior to DDMIX and SUPERTRAPP. 相似文献
102.
Balaji V. S. Iyer Sachin Shanbhag Vinay A. Juvekar Ashish K. Lele 《Journal of Polymer Science.Polymer Physics》2008,46(21):2370-2379
In a topologically constraining environment the size of a flexible nonconcatenated ring polymer (macrocycles) and its dynamics are known to differ from that of linear polymers. Hence, the diffusion coefficient of ring polymers can be expected to be different from linear chains. We present here scaling arguments for the concentration and molecular weight dependence of self‐diffusion coefficient of ring polymers in semidilute solutions, and show that contrary to expectations these scaling relations are identical to what is known for linear polymers. At higher concentrations excluded volume interactions arising from possibilities of segmental overlap can become effective for large ring polymers. In this regime the diffusion coefficient of large ring polymers shows a relatively weaker dependence on concentration and molecular weight. ©2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2370–2379, 2008 相似文献
103.
Balasubramanian Sridhar Krishnan Ravikumar 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(5):o265-o267
Ropinirole hydrochloride, or diethyl[2‐(2‐oxo‐2,3‐dihydro‐1H‐indol‐4‐yl)ethyl]ammonium chloride, C16H25N2O+·Cl−, belongs to a class of new non‐ergoline dopamine agonists which bind specifically to D2‐like receptors with a selectivity similar to that of dopamine (D3 > D2 > D4). The N atom in the ethylamine side chain is protonated and there is a hydrogen bond between it and the Cl− ion. In the crystal structure, two cations and two anions form inversion‐related cyclic dimers via N—H⋯Cl hydrogen bonds. 相似文献
104.
The generalized linear complementarity problem revisited 总被引:5,自引:0,他引:5
Given a vertical block matrixA, we consider in this paper the generalized linear complementarity problem VLCP(q, A) introduced by Cottle and Dantzig. We formulate this problem as a linear complementarity problem with a square matrixM, a formulation which is different from a similar formulation given earlier by Lemke. Our formulation helps in extending many
well-known results in linear complementarity to the generalized linear complementarity problem. We also show that the class
of vertical block matrices which Cottle and Dantzig's algorithm can process is the same as the class of equivalent square
matrices which Lemke's algorithm can process. We also present some degree-theoretic results on a vertical block matrix. 相似文献
105.
106.
Karr AF Feng J Lin X Sanil AP Young SS Reiter JP 《Journal of computer-aided molecular design》2005,19(9-10):739-747
We present a method for performing statistically valid linear regressions on the union of distributed chemical databases that preserves confidentiality of those databases. The method employs secure multi-party computation to share local sufficient statistics necessary to compute least squares estimators of regression coefficients, error variances and other quantities of interest. We illustrate our method with an example containing four companies' rather different databases. 相似文献
107.
H. H. Kagiwada R. E. Kalaba A. Schumitzky R. Sridhar 《Journal of Optimization Theory and Applications》1968,2(4):226-229
The final step in the mathematical solution of many problems in mathematical physics and engineering is the solution of a linear, two-point boundary-value problem such as $$\begin{gathered} \ddot u - q(t)u = - g(t), 0< t< x \hfill \\ (0) = 0, \dot u(x) = 0 \hfill \\ \end{gathered} $$ Such problems frequently arise in a variational context. In terms of the Green's functionG, the solution is $$u(t) = \int_0^x {G(t, y, x)g(y) dy} $$ It is shown that the Green's function may be represented in the form $$G(t,y,x) = m(t,y) - \int_y^x {q(s)m(t, s) m(y, s)} ds, 0< t< y< x$$ wherem satisfies the Fredholm integral equation $$m(t,x) = k(t,x) - \int_0^x k (t,y) q(y) m(y, x) dy, 0< t< x$$ and the kernelk is $$k(t, y) = min(t, y)$$ 相似文献
108.
109.
Sridhar L. Chennuri B. C. Haldar 《Journal of Radioanalytical and Nuclear Chemistry》1984,84(1):197-200
A method has been developed for the extraction of Zn(II) with ethylthioacetoacetate (HETAcAc) into ethyl acetate from an alkaline medium. Various parameters affecting the extraction of Zn(II) have been investigated. The stoichiometry of the extracted species has been determined by the slope-ratio method. 相似文献
110.
H. Kagiwada R. E. Kalaba A. Schumitzky R. Sridhar 《Journal of Optimization Theory and Applications》1968,2(3):157-163
The mathematical treatment of many problems in mathematical physics requires the minimization of a quadratic functional. It is shown that the optimizing function can be viewed as the solution of the familiar Euler equation, subject to boundary conditions, or as the solution of a certain Fredholm integral equation, or as the solution of an initial-value (Cauchy) problem. Each formulation has certain analytic and computational advantages and disadvantages. 相似文献